Oil field operations often require the injection of a mixture of gaseous and liquid components to enhance the production of hydrocarbons from a hydrocarbon-bearing formation. Wet steam, i.e., steam that has a water phase and a vapor phase, is often injected in hydrocarbon fields having heavy hydrocarbons to assist the movement of the hydrocarbons within the formation toward a production well. Typically, a 10% to 80% quality steam is injected into the formation. As the liquid and vapor phases travel down the injection tubing toward the formation, the liquid phase tends to segregate out along the walls of the tubing while the vapor phase remains within the center of the tube. In order to adequately assess the quality of steam being injected into the formation, it is necessary to have a uniform steam quality or liquid and vapor mixture as it enters the formation.
Steam flow agitators are placed in the string of injection tubing to insure the mixing of the liquid and vapor phases. Many of these flow agitators are baffles or restrictions in the tubing which cause the vapor and liquid phases to intermix. However, these baffles can cause undesirable back pressure within the injection tubing and may eventually clog unless high-purity water is used. The clogging can occur more rapidly if additives such as surfactants, foaming agents, or other chemicals are utilized along with the injected steam. More importantly, well logging survey tools, such as temperature, pressure, and spinner tools, cannot be used because of the restriction in the injection tubing.
Thus, it would be highly desirable to have an agitator which intermixes the liquid and vapor phases prior to injection but does not present a blockage within the tubing and permits the use of logging tools to pass through the flow agitators.